Effects of voglibose and nateglinide on glycemic status and coronary atherosclerosis in early-stage diabetic patients

Background: Postprandial hyperglycemia and hyperinsulinemia have been considered as important determinants for the development of atherosclerosis. However, it remains to be elucidated whether correction of the postprandial glycemic status prevents atherosclerotic changes. Methods and Results: The DIANA (DIAbetes and diffuse coronary NArrowing) study is a prospective randomized open-label multicenter trial. The 302 patients with coronary artery disease (CAD), impaired glucose tolerance/diabetes mellitus (DM) pattern according to 75-g oral glucose tolerance test and HbA _1c <6.9% were randomly assigned to life-style intervention (n=101), voglibose (0.9 mg/day, n=100) or nateglinide treatment (180 mg/day, n=101). We compared 1-year coronary atherosclerotic changes evaluated by quantitative coronary arteriography. Although voglibose significantly increased the number of patients with normal glucose tolerance at 1 year, there were no significant differences in coronary atherosclerotic changes at 1 year. However, overall, less atheroma progression was observed in patients in whom glycemic status was improved at 1 year (%change in total lesion length: 3.5% vs. 26.2%, P<0.01, %change in averaged lesion length: 0.7% vs. 18.6%, P=0.02). Conclusions: Although coronary atherosclerotic changes were similar for voglibose and nateglinide, an improvement in glycemic status at 1 year was associated with less atheroma progression regardless of the treatment. Our findings underscore the management of glycemic abnormality to prevent coronary atherosclerotic changes in Japanese early-stage DM patients with CAD.